Siemens 3TK28 Manual page 191

Procedure for spring-loaded terminal blocks
Step Operating instruction
1 To release the terminal spring, insert the 3-mm
flat-head screwdriver into the square opening
of the spring-loaded terminal until it engages.
Please observe a 10° horizontal angular
deviation of the screwdriver to the oval
opening.
2 Insert the cable into the oval opening as far as
it will go.
3 Hold the cable in the spring-loaded terminal.
4 Remove the screwdriver.
5 Pull on the cable to ensure it is tight.
See also
Connecting terminal blocks (Page 39)
3TK28 safety relays
Manual, 07/2016, NEB926157502000/RS-AB/003
Connection
5.2 Connecting terminal blocks
Figure
191